Specs would really help. Laptop or desktop?
Some things you can do to give your CPU more time:
- Search %appdata%, open Exanima folder, open Exanima.ini, lower the FPSLimit to something like 30-35 whenever you play Campaign; this will reduce the slowdown the most
- Tweak the graphics settings, then resolution as necessary
- Do not leave the paperdoll open during Campaign play
- Sprinting takes a considerable toll on performance for some reason, so don't use it until you've done the next item
- Keep the undead population low (I have to kill about 5 undead in the beginning before the game levels off)
- If all else fails, then you could try playing in window mode at lower res than 720p and lower Windows Desktop color to 16-bit (right-click desktop->Screen Resolution->Advanced settings->Monitor)